/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */
#ifndef http_parser_h
#define http_parser_h
#ifdef __cplusplus
extern "C" {
#endif
    
    /* Also update SONAME in the Makefile whenever you change these. */
#define HTTP_PARSER_VERSION_MAJOR 2
#define HTTP_PARSER_VERSION_MINOR 3
#define HTTP_PARSER_VERSION_PATCH 0
    
#include <sys/types.h>
#if defined(_WIN32) && !defined(__MINGW32__) && (!defined(_MSC_VER) || _MSC_VER<1600)
#include <BaseTsd.h>
#include <stddef.h>
    typedef __int8 int8_t;
    typedef unsigned __int8 uint8_t;
    typedef __int16 int16_t;
    typedef unsigned __int16 uint16_t;
    typedef __int32 int32_t;
    typedef unsigned __int32 uint32_t;
    typedef __int64 int64_t;
    typedef unsigned __int64 uint64_t;
#else
#include <stdint.h>
#endif
    
    /* Compile with -DHTTP_PARSER_STRICT=0 to make less checks, but run
     * faster
     */
#ifndef HTTP_PARSER_STRICT
# define HTTP_PARSER_STRICT 1
#endif
    
    /* Maximium header size allowed. If the macro is not defined
     * before including this header then the default is used. To
     * change the maximum header size, define the macro in the build
     * environment (e.g. -DHTTP_MAX_HEADER_SIZE=<value>). To remove
     * the effective limit on the size of the header, define the macro
     * to a very large number (e.g. -DHTTP_MAX_HEADER_SIZE=0x7fffffff)
     */
#ifndef HTTP_MAX_HEADER_SIZE
# define HTTP_MAX_HEADER_SIZE (80*1024)
#endif
    
    typedef struct http_parser http_parser;
    typedef struct http_parser_settings http_parser_settings;
    
    
    /* Callbacks should return non-zero to indicate an error. The parser will
     * then halt execution.
     *
     * The one exception is on_headers_complete. In a HTTP_RESPONSE parser
     * returning '1' from on_headers_complete will tell the parser that it
     * should not expect a body. This is used when receiving a response to a
     * HEAD request which may contain 'Content-Length' or 'Transfer-Encoding:
     * chunked' headers that indicate the presence of a body.
     *
     * http_data_cb does not return data chunks. It will be called arbitrarily
     * many times for each string. E.G. you might get 10 callbacks for "on_url"
     * each providing just a few characters more data.
     */
    typedef int (*http_data_cb) (http_parser*, const char *at, size_t length);
    typedef int (*http_cb) (http_parser*);
    
    
    /* Request Methods */
#define HTTP_METHOD_MAP(XX)         \
XX(0,  DELETE,      DELETE)       \
XX(1,  GET,         GET)          \
XX(2,  HEAD,        HEAD)         \
XX(3,  POST,        POST)         \
XX(4,  PUT,         PUT)          \
/* pathological */                \
XX(5,  CONNECT,     CONNECT)      \
XX(6,  OPTIONS,     OPTIONS)      \
XX(7,  TRACE,       TRACE)        \
/* webdav */                      \
XX(8,  COPY,        COPY)         \
XX(9,  LOCK,        LOCK)         \
XX(10, MKCOL,       MKCOL)        \
XX(11, MOVE,        MOVE)         \
XX(12, PROPFIND,    PROPFIND)     \
XX(13, PROPPATCH,   PROPPATCH)    \
XX(14, SEARCH,      SEARCH)       \
XX(15, UNLOCK,      UNLOCK)       \
/* subversion */                  \
XX(16, REPORT,      REPORT)       \
XX(17, MKACTIVITY,  MKACTIVITY)   \
XX(18, CHECKOUT,    CHECKOUT)     \
XX(19, MERGE,       MERGE)        \
/* upnp */                        \
XX(20, MSEARCH,     M-SEARCH)     \
XX(21, NOTIFY,      NOTIFY)       \
XX(22, SUBSCRIBE,   SUBSCRIBE)    \
XX(23, UNSUBSCRIBE, UNSUBSCRIBE)  \
/* RFC-5789 */                    \
XX(24, PATCH,       PATCH)        \
XX(25, PURGE,       PURGE)        \
/* CalDAV */                      \
XX(26, MKCALENDAR,  MKCALENDAR)   \

    enum http_method
    {
#define XX(num, name, string) HTTP_##name = num,
        HTTP_METHOD_MAP(XX)
#undef XX
    };
    
    
    enum http_parser_type { HTTP_REQUEST, HTTP_RESPONSE, HTTP_BOTH };
    
    
    /* Flag values for http_parser.flags field */
    enum flags
    { F_CHUNKED               = 1 << 0
        , F_CONNECTION_KEEP_ALIVE = 1 << 1
        , F_CONNECTION_CLOSE      = 1 << 2
        , F_CONNECTION_UPGRADE    = 1 << 3
        , F_TRAILING              = 1 << 4
        , F_UPGRADE               = 1 << 5
        , F_SKIPBODY              = 1 << 6
    };
    
    
    /* Map for errno-related constants
     *
     * The provided argument should be a macro that takes 2 arguments.
     */
#define HTTP_ERRNO_MAP(XX)                                           \
/* No error */                                                     \
XX(OK, "success")                                                  \
\
/* Callback-related errors */                                      \
XX(CB_message_begin, "the on_message_begin callback failed")       \
XX(CB_url, "the on_url callback failed")                           \
XX(CB_header_field, "the on_header_field callback failed")         \
XX(CB_header_value, "the on_header_value callback failed")         \
XX(CB_headers_complete, "the on_headers_complete callback failed") \
XX(CB_body, "the on_body callback failed")                         \
XX(CB_message_complete, "the on_message_complete callback failed") \
XX(CB_status, "the on_status callback failed")                     \
\
/* Parsing-related errors */                                       \
XX(INVALID_EOF_STATE, "stream ended at an unexpected time")        \
XX(HEADER_OVERFLOW,                                                \
"too many header bytes seen; overflow detected")                \
XX(CLOSED_CONNECTION,                                              \
"data received after completed connection: close message")      \
XX(INVALID_VERSION, "invalid HTTP version")                        \
XX(INVALID_STATUS, "invalid HTTP status code")                     \
XX(INVALID_METHOD, "invalid HTTP method")                          \
XX(INVALID_URL, "invalid URL")                                     \
XX(INVALID_HOST, "invalid host")                                   \
XX(INVALID_PORT, "invalid port")                                   \
XX(INVALID_PATH, "invalid path")                                   \
XX(INVALID_QUERY_STRING, "invalid query string")                   \
XX(INVALID_FRAGMENT, "invalid fragment")                           \
XX(LF_EXPECTED, "LF character expected")                           \
XX(INVALID_HEADER_TOKEN, "invalid character in header")            \
XX(INVALID_CONTENT_LENGTH,                                         \
"invalid character in content-length header")                   \
XX(INVALID_CHUNK_SIZE,                                             \
"invalid character in chunk size header")                       \
XX(INVALID_CONSTANT, "invalid constant string")                    \
XX(INVALID_INTERNAL_STATE, "encountered unexpected internal state")\
XX(STRICT, "strict mode assertion failed")                         \
XX(PAUSED, "parser is paused")                                     \
XX(UNKNOWN, "an unknown error occurred")
    
    
    /* Define HPE_* values for each errno value above */
#define HTTP_ERRNO_GEN(n, s) HPE_##n,
    enum http_errno {
        HTTP_ERRNO_MAP(HTTP_ERRNO_GEN)
    };
#undef HTTP_ERRNO_GEN
    
    
    /* Get an http_errno value from an http_parser */
#define HTTP_PARSER_ERRNO(p)            ((enum http_errno) (p)->http_errno)
    
    
    struct http_parser {
        /** PRIVATE **/
        unsigned int type : 2;         /* enum http_parser_type */
        unsigned int flags : 6;        /* F_* values from 'flags' enum; semi-public */
        unsigned int state : 8;        /* enum state from http_parser.c */
        unsigned int header_state : 8; /* enum header_state from http_parser.c */
        unsigned int index : 8;        /* index into current matcher */
        
        uint32_t nread;          /* # bytes read in various scenarios */
        uint64_t content_length; /* # bytes in body (0 if no Content-Length header) */
        
        /** READ-ONLY **/
        unsigned short http_major;
        unsigned short http_minor;
        unsigned int status_code : 16; /* responses only */
        unsigned int method : 8;       /* requests only */
        unsigned int http_errno : 7;
        
        /* 1 = Upgrade header was present and the parser has exited because of that.
         * 0 = No upgrade header present.
         * Should be checked when http_parser_execute() returns in addition to
         * error checking.
         */
        unsigned int upgrade : 1;
        
        /** PUBLIC **/
        void *data; /* A pointer to get hook to the "connection" or "socket" object */
    };
    
    
    struct http_parser_settings {
        http_cb      on_message_begin;
        http_data_cb on_url;
        http_data_cb on_status;
        http_data_cb on_header_field;
        http_data_cb on_header_value;
        http_cb      on_headers_complete;
        http_data_cb on_body;
        http_cb      on_message_complete;
    };
    
    
    enum http_parser_url_fields
    { UF_SCHEMA           = 0
        , UF_HOST             = 1
        , UF_PORT             = 2
        , UF_PATH             = 3
        , UF_QUERY            = 4
        , UF_FRAGMENT         = 5
        , UF_USERINFO         = 6
        , UF_MAX              = 7
    };
    
    
    /* Result structure for http_parser_parse_url().
     *
     * Callers should index into field_data[] with UF_* values iff field_set
     * has the relevant (1 << UF_*) bit set. As a courtesy to clients (and
     * because we probably have padding left over), we convert any port to
     * a uint16_t.
     */
    struct http_parser_url {
        uint16_t field_set;           /* Bitmask of (1 << UF_*) values */
        uint16_t port;                /* Converted UF_PORT string */
        
        struct {
            uint16_t off;               /* Offset into buffer in which field starts */
            uint16_t len;               /* Length of run in buffer */
        } field_data[UF_MAX];
    };
    
    
    /* Returns the library version. Bits 16-23 contain the major version number,
     * bits 8-15 the minor version number and bits 0-7 the patch level.
     * Usage example:
     *
     *   unsigned long version = http_parser_version();
     *   unsigned major = (version >> 16) & 255;
     *   unsigned minor = (version >> 8) & 255;
     *   unsigned patch = version & 255;
     *   printf("http_parser v%u.%u.%u\n", major, minor, patch);
     */
    unsigned long http_parser_version(void);
    
    void http_parser_init(http_parser *parser, enum http_parser_type type);
    
    
    /* Executes the parser. Returns number of parsed bytes. Sets
     * `parser->http_errno` on error. */
    size_t http_parser_execute(http_parser *parser,
                               const http_parser_settings *settings,
                               const char *data,
                               size_t len);
    
    
    /* If http_should_keep_alive() in the on_headers_complete or
     * on_message_complete callback returns 0, then this should be
     * the last message on the connection.
     * If you are the server, respond with the "Connection: close" header.
     * If you are the client, close the connection.
     */
    int http_should_keep_alive(const http_parser *parser);
    
    /* Returns a string version of the HTTP method. */
    const char *http_method_str(enum http_method m);
    
    /* Return a string name of the given error */
    const char *http_errno_name(enum http_errno err);
    
    /* Return a string description of the given error */
    const char *http_errno_description(enum http_errno err);
    
    /* Parse a URL; return nonzero on failure */
    int http_parser_parse_url(const char *buf, size_t buflen,
                              int is_connect,
                              struct http_parser_url *u);
    
    /* Pause or un-pause the parser; a nonzero value pauses */
    void http_parser_pause(http_parser *parser, int paused);
    
    /* Checks if this is the final chunk of the body. */
    int http_body_is_final(const http_parser *parser);
    
#ifdef __cplusplus
}
#endif
#endif